SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '948a9231656f4355a14e0c12f22b96c978c9a277ee8c76382d717e156bbe31bb' 
  AND token = 'fwvGizVfaqFXanp8ba/E2QBmMSCYYzby0KKHejoi2gU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}