Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c91c867cad93cb9807e039e1a1379318f4ea4d22697f22cecb82a4e1f7bfa0c1' 
  AND token = 'uCIDikXjmPQ1xOB+SjZJ+2Ydg321YxdeXCoGcrrevQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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