SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb74580bcb496074f98b159a3c805a6dcd3fee23ff1e4b65688624eb54a6e099' 
  AND token = '2mDIrou//phzpsXz4kuEoU6M0P6XCMoZ+kBh2c1vi4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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