SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9f592a80773033766f83afbbe7951b0311e999dac38663d61867a668e1c701d' 
  AND token = 'LTBXIyilK7QBGQSHzSYLojgUDgD6z7cM4zsVnbHHCCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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