SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3237c1a5dfedb62d95eeeee8298c4815d9331aaf854eec4e54a8bbd8965be096' 
  AND token = 'SBgTLp6DBTBAV/KpgRN2wuYjdc30kGPCb+mYDcttGZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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