SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adce2f043c5754dcd5ffc47df9650eb4620a00b99f0b02ddf8f24bf9d0a7f9b7' 
  AND token = 'hrdhrM9ph5dMytb6j/R9vz+28kwbOCwYF5qv7s86tMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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