SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1f82923e2d1610cf990f0b537dae7f16fd37df59b00d228307b47bc6159aa4b' 
  AND token = 'k10qHhvZBSmMx9mo7pat9pH7JBMxHcPTiKGtojJXEv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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