SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43a7dcdedd2212145c0757545e56f3773923258386cee229588f8f871ca9a92a' 
  AND token = 'ieb675dfw29xNrSE/DtToWrOVabvg6Gj7m5gUKSDSW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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