SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a54e7c3c58af0814c7603da0e891139df917ade4b4792b763c2476ea95cb8a8' 
  AND token = 'tF/MhbT1XeYFAyCPVzgKQd6zRL+bRwO1UdQ+yQ3EYjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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