SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66b8e65c26374bc992363425ad92df12bd81925349fa0cd86848a3706843b8f5' 
  AND token = 'DXrNjgBxo2gyablbzbHkZC/z9dzc0jYMuR4/L9/Mtwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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