SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab36149b3a2eef44cf155ab1173db85d768b7cd545734f727f5f40aa4f53726b' 
  AND token = 'FBYn9KL2yLXozSyg+NTJiZdOwn6Nh0DCsaLeP+ko9vY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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