SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdaa4870d2a6185793e46a2bd5102debf9b825230cc4c4964901b64dbd3314af' 
  AND token = 'zA7ay6mJKLYTFsjN37pNhLxSBFJCK6MJvyIeaeg+H58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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