SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba7b82a74f7b960edbc74a041bb090d33a2cf874124199866bb1e74e9591bb30' 
  AND token = 'SMN0ZqmgSDx3v1FcsQXgMDyp0m9TnOX2yDiqdjAT25s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}