SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5e79df5c5a9cd0ae42aa2245eabc001224aba86339b7c83268ba42e06b21e38' 
  AND token = '7qLaEIAy+dvkqCrfcZ1rJmbp/kXtVwgDco20M+lVEnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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