SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25e1260010e902540167b49268a8788faf39a319866ed0dda0cf23f262630328' 
  AND token = 'FVGTy4X4LG1J68CkKoE7rrBDv1IyRwkDXpdaMdTcE7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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