SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df06611e774810fb7e14be4815cad77f07afb6d6f46091ee8b1f5aaeea86c0ef' 
  AND token = 'CJQiCyEzSD02rz97ruhhEjAdVtRKvYlbhf1rwO/l/VY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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