SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b2f40717055d9901827fff63d7a2b51796f6161973f3851a67db802019656d2' 
  AND token = 'IHmPIUDSK/QKDfiMdWBN6Yg4xtG7NkURvTyklUUROIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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