SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d5cbafe555cbb6ca796ea01e07649ced1d32dc8e848eb5f47ed370b1a7e86b0' 
  AND token = 'QhQHbkrKWtOhR+iqT2A5nlOiWHyrBI1GdHkzd8Tmb/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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