SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '70cce1961a00757e48197c1995313c2ce96a39a58fc3d8966813f3c39255c0ad' 
  AND token = '40qvk4ku/V03IF8Kyzrmu30IDwQCykqzg2NjWgKiGas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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