SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7decf2d5f48094a0dce506cc120316b4cbbaca62bcd244bf99213dda713d964' 
  AND token = 'HVJWTXMSQGdUIV49bVbBHRPTK8iqe7lr+489q/D+OM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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