SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd164a99729ad964498b1311b22e7e93c44a44c48031654efdd472c5c7968bea9' 
  AND token = 'pCU6zWDVis1REbTFbJttGs/aErN00XIOZmVYgVPgLSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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