SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8902f6fa6a589a56d7208ed665bf1108f630b06240ea80d5c022ea5ff42e762d' 
  AND token = 'bAedSIV36hIltlCzdyL9q+x2ejrOU15LdP3ueEEJ4XY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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