SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e8620b37f252621f4d5ff515af2920b3dcc65b291043c771dac98b9e85e3efb' 
  AND token = 'prV3dYcLrZ7vQrxT5QPv58X7HGJgwEFRXBOyeX1dq+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}