SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd9c74e3ac253b5d15b78a5192dadcb7d77905753c62fd4f80432a175f0ea79d' 
  AND token = 'eaz0NN7wA1goamq8o62vK4NdHjTD4zump6F+8nRdoSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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