SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e95492739aa5eecf71c9698a5da2235c562905616985d176abb534621610363' 
  AND token = 'jS0d1xGwqpmWldXSrc2r2vkUV4/jVetntIXbDaqO2Vc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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