SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '780965e47cc163d58a2b2cad13deb89b822324014eff238da0a85e91dec8ee2c' 
  AND token = 'Nfifwuy7zFW0JCRfWXYQUnHdP0dRs6Yt2AW7Nyl6iGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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