SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52cfee4802eea7f18306f7611b97d6d437a13cbd7d5e11a1810f5f55d19f7345' 
  AND token = 'nhczSzEvEm/pi66CgGKkOB2iq5XyowJLshHdIvlfktg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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