SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a689b7e7e71fd6f2296846aa31cb015760ddaad3f0a208925e42e3c3afdba145' 
  AND token = 'yBwdU8THozWPRdCOcmkRR+g55/Jkn6A2sQ7qmzmLgJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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