SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bbe414c92fec5f5425fab148b6a37df74c6fa781758ead7c21b3e53da5bc2a2' 
  AND token = 'gjBHDjqOJ+IT4hOT+Hjaxmf1+J2/syrT35GaYvJNtBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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