SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cad5e8a91cc453e6184abb33f39b0630916524d1188c54ed4c5dcc260a8d6e66' 
  AND token = 'm3afKB/qaQ08tBMEigNtlzs0+fkrpySGIQC/8S6xzKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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