SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30705306ebba6b454c52137eafe2c18dc82151379e85765019caabf5526a3640' 
  AND token = 'z4sDdFeGZQNrjmYABUuVVx3C+sIEJkqsagm+5xa1D3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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