SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb245fbc59c333717cc3ab4a4ebb6a291468531132fbf83fccb0883b4ffc587b' 
  AND token = 'bQgjcrzw/K4T0vwNl+r+wahyiOjVHILtbt8y3Bkfbmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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