SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0032749b0125c55c0946214ee511ea636b964bcef46010849bd3a23ea45d002' 
  AND token = 'ESlkSRIzkU+fSz59A+hxoMTuHWklaKjjy5kXR9GbBH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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