SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d1a2a0b41738263955656dabf98b90fef2c8175ed1622386c47f0e8579487d3' 
  AND token = 'RbrWB3BHzRDQV8Z2GSEvk3fKJmMrzCIAcP4oU1FAhh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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