SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c6b216dfc2936a84f31662d39fa61f3e22d0434b18adbfe11e11cd9e8514c4b' 
  AND token = 'Ga8DCeYBeFT0ylQZKNR9hq2s7/xJ6FiVhKFYG1vT2lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}