SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e49cd0262d9f850ddfc9dd6b820423636618bdb5b0cf291c38031879851d5e2' 
  AND token = 'NpJIX6C+UKmV3GluCZvpUh77dZetKObutxSMw5YywAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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