SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16719cee5ed3fa4f9c3c4889a915d3b383748673ee24a0daf9bec388cfb75550' 
  AND token = 'zPkKrKarPGRLuuL69VR0mwhQS4g6RPpWeu7rkUJyd5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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