SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25fafb1295100ae81115076d46a4d958614b267fb06f48522f24aac5ee6abe62' 
  AND token = '+cBrSfxu5+w3XJIN/nC8liOmR/HM30hNjzjdYg2HqEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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