SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc0bf0fd25165260e6d258a7bd11fce667200b605760853e8bafca565eef9aab' 
  AND token = 'H1wyY62/MlbBsQt34xToQ/TAyFuQzH8pl03jcbsK+EM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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