SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6add9b01cef351791b29ba22426c72043bb86d4498a5964990b7fdc4b734224' 
  AND token = 'weVCcqh5teJH8Cl6R/tX5UjZb0TCUFdCGfvW+tGOy9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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