SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54025a1ffc8f9e0b0db80bc214f1e5b36a51b5760eae25642c23c56a9e07ea9c' 
  AND token = '8grx4PjNDRVozgy3LbL4HN/AkAA5PzZ2pFHJCEoNVVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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