SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '671f45eabfb6346dd6c7f89fafc5426eb389c3b1dfe630eca4b11c06ca827296' 
  AND token = 'OZsP2jSmVpoCPvWvWMOwbw8nOceWGGdDRdAHc1ZtANc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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