SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd277cbc94f1e54a92db46bd4cabcaaad5980d47594388df4ee90b887441a83f0' 
  AND token = 'BjYb9SjQmFX7Yz7c5THkWIc6YniaczjOa+Oc4LPKfMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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