SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61f068ce8f09d2b1eb41877498b534fcbda35fd5baaa973fea48e8295f6dde70' 
  AND token = 'oO5iv1TNwAA4hGax3w1Q0TUvnoAnk+KHWmbUntlZkXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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