SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a62573e1c5cfb0b838d10229b5744ddd30012322eb5eba92081e936bea2dac0' 
  AND token = 'A0jCoU+yhAKMRTi3rsIwomQEdcZ4eYMVfbehkic/D3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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