SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '343151a01ac0383adfc7189762d5629fb5938e6bcfa4915e5d202b7d99caf9c6' 
  AND token = 'SzhqR5hiDlDgMN1KKzdYmgm2DG3DxwQsJF2Jncc/bVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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