SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c66bfb3fe3d84a9065d75a54175fdc42636307041b9710e00543ea0b02f2cdbc' 
  AND token = 'XunprEXFz/M+jijNxON3V1Egd92q1J1rz2lmLhnX8lY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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