SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e42a0a35e8f4041f9bcaad2d250c9099c7f3efa70ecbe3f4087480900fb1171f' 
  AND token = 'Jy+4zNiVvRNm+Sjz4FngV26iK2ZCSt9xvhDnnfo3H5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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