SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fcb63360a224d8fa546ea2a2e10b35157f2c11c375e2e19241ffd0e0d4dd2d6' 
  AND token = 'YZuNR4flsjel2vNLPzafQGxwDWOUWCrCnQj/6o8zpVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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