SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12ec509127987fae57c4b0879c60fadcb85754d37bade40e210a33d558d8966b' 
  AND token = 'KDF+hJ3/VdS0iLaimqPvp+RZjiY+Waqok3HR3Dq+26w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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