SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c649c932f26a27f2d39f16727b026907ff510242c3b1098f11597d06fa55866' 
  AND token = 'h3HuVZTEyGpuR1pkpfc04KAtUaHXEjlcdRsdlMiQDhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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