SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c280b5d85f962656d7ba0c3cdde0c7ae67879e80568aae1fe5360d4957607e28' 
  AND token = 'NKlhAlgoZvCXzloQ8uPAvPQW0FjofP87KYFKwOZEeDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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