SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a9ada7c034ef0bc5976206692b304fca86a78d2fc5d432ec662df2a4b88ccab' 
  AND token = 'WyRLqIDVPWX2FcYDTG83/UkNSiDnIIQwKQg892Q13uc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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